Performance of Amblypharyngodon mola with Barbodes gonionotus, Cyprinus carpio and Macrobrachium rosenbergii in rice-fish culture system

An experiment was conducted to assess the performance of mola (Amblyphmyngodon mola) in rice fish culture system with freshwater prawn Macrobrachium rosenbergii), Thai silver barb (Bm·bades ganianotus) and common carp (Cyprinus cmpia) for a period of 4 months at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, Bangladesh. Four treatments viz., treatment-I (T1) with A. mala and M. rosenbergii; treatmen t-II (T2) with A. mala, M. rosenbergii and B. gonianatus ; treatmentIII (T3) with A. mala, 1Vf. rosenbergii and C. cmpia, and treatment- IV (T4) as control (without fish) were used in triplicate. All treatments were equally fertilized with urea (200 kg/ha), TSP (150 kg/ha) and MP (75 kg/ha). The mean values of water quality parameters viz., temperature, dissolved oxygen, pH, nitrate-nitrogen showed a very small variations among different treatments, but phosphate-phosphorus and chlorophyll-a were relatively higher in T4 without fish (i.e., control). The fish production of 480.5 kg/ha in T3 was significantly higher than that of 355.6 kg/ha T2 and 223.8 kg/ha in T 1• The values of soil organic matter, total-nitrogen, phosphorus and potassium at harvest were significantly (P<0.05) higher in the treatments with fish than without fish, but pH did not show any significant differences. The yield of rice grain and straw was also obtained significantly (P<0.05) higher in the treatments with fish. The increase in grain was higher over the control by 11.81%, 9.41% and 14.76% and that in straw was by 9.83%, 4.77% and 13.29% in Tl> T2, and T3 respectively.

Observation on some of the environmental parameters and feed quality of selected golda (Macrobrachium rosenbergii) farms in Bangladesh

A study was conducted to ascertain the existing farm water, effluent and feed quality of selected giant freshwater prawn farms from major prawn farming areas (Bagerhat Sadar, Noakhali Sadar and Mymensingh) of Bangladesh during July to November 2005. Water quality parameters such as the mean values of dissolved oxygen, alkalinity, nitrite-nitrogen, phosphate-phosphorus and ammoniacal nitrogen did not show any significantly differences among the farming areas. Whereas significant differences (p < 0.05) were observed in the mean values of temperature, secchi disc visibility, pH and chlorophyll a. However, all the water quality parameters in the farming areas were within the suitable range for prawn culture. There was no significant variation in nutrients concentration of discharged effluent among the prawn farming areas. All of the nutrients measured in effluent water were within the acceptable range and did not seem to pose a direct threat to the recipient environment. The analysed crude protein contents of commercial CP, Quality and Saudi-Bangla prawn feeds were 31.84%, 27.21% and 28.97%, respectively, whereas all analysed farm made feeds were less than 25%. The other nutrients of prawn feeds varied largely with the source of feeds and ingredients used to prepare feed. The annual yield of prawn varied from 320.4 to 512.6 kg/ha (mean 412.3 kg/ha) depending on the management system.

Disease problems in shrimp sector in Khulna district of Bangladesh: a question of sustainability

Disease is the main restraining factor for the development of shrimp sector in Bangladesh. Both brackish water shrimp bagda (Penaeus monodon) and freshwater prawn golda, (Macrobrachium rosenbergii) farming in Bangladesh have been facing disease problem. A study on disease outbreak in both brackish water and freshwater small-scale shrimp farms (gher) in Khulna district was carried out through interviewing randomly selected 3-5% of shrimp farmers with a structured questionnaire during March to December, 2002. The study showed that 97% bagda farming ghers and 80% golda farming ghers were affected by disease. White spot disease was the severe disease for bagda, whereas, antenna rot was the main disease for freshwater prawn. Change of water and liming were carried out as control measures of disease for bagda shrimp farming, while it was only liming for golda farming. A small number of shrimp farmers (15%) used chemicals for treatment of shrimp diseases. Development of suitable farming technology to prevent disease contamination and innovation of proper treatments for diseases are required to overcome the disease problems for sustainable shrimp farming in Bangladesh.

Effects of supplemental feed and fertilizer on growth and survival of Macrobrachium rosenbergii (de Man) post larvae in pond nursery system

The study was conducted to compare the performance of different nursing practices of giant freshwater prawn (Macrobrachium rosenbergii) post-larvae (PL). Three treatments such as only fertilizers (T1), fertilizers with 5% supplementary feed (local feed) (T2), and 10% commercial feed (T3) were applied in the nursing system of prawn PLs in earthen pond. An earthen pond (315m²) was divided into nine equal small ponds by fine meshed nylon nets. Feeds were used once daily on a tray placed near the pond bottom. There was a significant difference (p<0.05) in some water quality parameters like pH and total alkalinity, but all measured water quality parameters viz. water temperature, transparency, dissolved oxygen and ammonia-nitrogen were within the acceptable range for nursing of prawn PL. The results showed that the mean final lengths of prawn post-larvae were 6.3±0.07 cm, 7.12±0.22 cm and 8.17±0.16 cm in T1, T2 and T3, respectively. There were significant difference (p<0.05) in mean final length of prawn PL among the treatments. Significantly higher (p<0.05) average daily weight gain was observed in T3 (0.071 ±0.007 g) than in T2 (0.052±0.006 g) and T1 (0.031 ±0.002 g). The specific growth rate (SGR) of T3 (8.81±0.26) was found significantly higher (p<0.05) than T2 (8.35±0.22) and T1 (7.42±0.11). Survival rate (%) was also significantly higher (p<0.05) in T3 (66.24±1.58) than in T2 (60.52±1.64) and T1 (53.86±2.71). Therefore, it may be concluded that the growth and survival in prawn nursery was better in commercial feed than only fertilizers and fertilizers with local feeds.

Artificial interspecific hybridization between Macrobrachium species

Viable F-1 hybrids were obtained from crosses of female Macrobrachium nipponense and male Macrobrachium hainanense involving spermatophore transfer and artificial insemination. This represents the first successful known case of hybridization of two Macrobrachium species by means of artificial insemination. The hatching rate was over 90%. About 20-60% of newly hatched larvae metamorphosed to postlarvae. The morphological characteristics of the hybrids resembled a combination of features of both parents. Malate dehydrogenase (MDH) and esterase (EST) isozyme electrophoresis indicated parents and F-1 hybrids showed co-dominant expression of the paternal and maternal alleles controlling the isozymes and confirmed the hybridization. (C) 2004 Elsevier B.V. All rights reserved.

The mitochondrial manganese superoxide dismutase gene in Chinese shrimp Fenneropenaeus chinensis: Cloning, distribution and expression

Manganese superoxide dismutase (MnSOD) plays an important role in crustacean immune defense reaction by eliminating oxidative stress. Knowledge on MnSOD at molecular level allows us to understand its regulatory mechanism in crustacean immune system. A novel mitochondrial manganese superoxide dismutase (mMnSOD) was cloned from hepatopancreas of Chinese shrimp Fenneropenaeus chinensis by 3' and 5' rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA consists of 1185 bp with a 660 bp open reading frame, encoding 220 amino acids. The deduced amino acid sequence contains a putative signal peptide of 20 amino acids. Sequence comparison showed that the mMnSOD of F. chinensis shares 88% and 82% identity with that of giant freshwater prawn Macrobrachium rosenbergii and blue crab Callinectes sapidus, respectively. mMnSOD transcripts were detected in hepatopancreas, hemocytes, lymphoid organ, intestine, ovary, muscle and gill by Northern blotting. RT-PCR analysis indicated that mMnSOD showed different expression profiles in shrimp hemocytes and hepatopancreas after artificial infection with while spot syndrome virus (WSSV). In addition, a fusion protein containing mMnSOD was produced in vitro. LC-ESI-MS analysis showed that two peptide fragments (-GDVNTVISLAPALK- and -NVRPDYVNAIWK-) of the recombinant protein were identical to the corresponding sequence of M. rosenbergii mMnSOD, and the enzyme activity of the refolded recombinant protein was also measured. (c) 2006 Elsevier Ltd. All rights reserved.

Effect of Pyridoxine on Growth, Metabolism and Cellular Activity of Macrobrachium rosenbergii

Effect of pyridoxine on growth, metabolism and cellular activity of freshwater prawn Macrobrachiuni rosenbergii was studied. Postlarvae (PL-10) of M. rosenbergii were fed with clam meat containing various concentrations of pyridoxine. After 30 days RNA and DNA of the abdominal tissues were estimated. Length, weight and RNA to DNA ratio increased significantly with increasing concentrations of pyridoxine. The effect of pyridoxine on the metabolic enzyme, malate dehydrogenase, was also studied. Vmax showed a significant decrease and the (Km) showed a significant increase in experimental groups compared to control.

Histological, Histochemical and Biochemical characterisation of male morphotypes of Macrobrachium rosenbergii (de Man)

This thesis entitled “Histological ,Histochemical and biochemical characterisation of male morphotypes of macrobrachium rosenbergii(De Man). The giant fresh water prawn Macrobrachium rosenbergii (de Man) is emerging as a prime candidate species in fresh water aquaculture as a global basis and therefore, receiving much attention in recent years.the present work was aimed at to study the histological variations, if any, in the reproductive system viz. testes, vas deferens including androgenic gland, hepatopancreas and the neurosecretory system viz. eye stalk, brain and thoracic ganglion among the male morphotypes and their transitional stages of M.rosenbergii from growouts. This study was also aimed at to bring out the histochemical variations, if any, in the reproductive system comprising of testes, vas deferens including androgenic gland and the hepatopancreas among the male morphotypes and their transitional stages collected from growouts. Biochemical characterisation of various male morphotyes and their transitional stages have also been attempted in order to find out biochemical evidence, if any, in the morphotypic transformation.Histological study of the testes of three male morphotypes viz., SM, SOC and SBC and their 'transitional stages viz., WOC, tSOC, WBC and OBC have been carried out with a view to unravel the structural and functional differences of the testes, if any, of these morphotypes. Studies on the lipid components viz., cholesterol, phospholipid and triglyceride In the muscle tissue and hepatopancreas have been carried out.

Isolation of a pathogenic strain of Vibrio alginolyticus from necrotic larvae of Macrobrachium rosenbergii (de Man)

Giant freshwater prawn, Macrobrachium rosenbergii (de Man), is an important commercial species with considerable export value, ideal for cultivation under low saline conditions and in freshwater zones (Kurup 1994). However, despite more than a decade of research on its larval production systems, vibriosis still hampers seed production resulting in high mortality rates. Among the different species of vibrios, Vibrio alginolyticus has been isolated frequently from diseased shrimp as the aetiological agent of vibriosis and has been described as a principal pathogen of both penaeids and nonpenaeids (Lightner 1988; Baticados, Cruz-Lacierda, de la Cruz, Duremdez-Fernandez, Gacutan, Lavilla- Pitogo & Lio-Po 1990; Mohney, Lightner & Bell 1994; Lee, Yu, Chen, Yang & Liu 1996). Vibrio fluvialis, V. alginolyticus, V. cholerae non-O1 (Fujioka & Greco 1984), Aeromonas liquifaciens and V. anguillarum (Colorni 1985) have been isolated from the larvae of M. rosenbergii. A profound relationship between the abundance of members of the family Vibrionaceae and larval mortality (Singh 1990) and the predominance of Vibrio in eggs, larvae and post-larvae of M. rosenbergii (Hameed, Rahaman, Alagan & Yoganandhan 2003) was reported. The present paper reports the isolation, characterization, pathogenicity and antibiotic sensitivity of V. alginolyticus associated with M. rosenbergii larvae during an occurrence of severe mass mortality at the ninth larval stage.

Influence of stocking densities in the nursery phase on the growth of Macrobrachium amazonicum reared in net pens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da intensidade luminosa no desenvolvimento larval do camarão-da-amazônia, Macrobrachium amazonicum

The effects of four light intensities (0; 2.8 +/- 0.9; 5,5 +/- 1,8 e 7,8 +/- 2,5 mu mol s(-1) m(-2), about 136.5 +/- 87.5; 273 +/- 43.8 e 390 +/- 125 lux, respectively) on survival, productivity, weight gain and larval development of Macrobrachium amazonicum were investigated. Four treatments with three replicate tanks were evaluated. Newly hatched larvae were held in black tanks (80.2 +/- 0.6 larvae L(-1)) filled with 50-L-brackish water (salinity of 10), in a recirculating system. Tanks were covered with shadow cloth allowing 35% and 70% light, respectively, to reach light intensities of 2.8 +/- 0.9 and 5.5 +/- 1.8 mu mol s(-1) m(-2) at the water surface. Complete absence of light (0 mu mol s(-1) m(-2)) was obtained covering the tanks with opaque black plastic, and full-light condition used no covering (7.8 +/- 2.5 mu mol s(-1) m(-2)). Observations showed that the survival rate was not affected by light intensity. Productivity and weight gain were higher under 7.8 +/- 2.5 mu mol s(-1) m(-2) light intensity than under 0 and 2.8 +/- 0.9 1 mu mol s(-1) m(-2) intensities (P<0.05). The larval development index was similar among the treatments under the different light intensities. However, from stage VII this index was increased slightly in the treatment under 7.8 +/- 2.5 mu mol s(-1) m(-2) light intensity. In conclusion, light intensity affects larval development of M. amazonicum. Values as high as 7.8 mu mol s(-1) m(-2) (about 390 lux) improve the larval performance by enhancing development, productivity and weight gain compared to lower values.

Sistema de recirculação e rotina de manejo para larvicultura de camarões de água doce Macrobrachium rosenbergii em pequena escala

A recirculating system and a matching management schedule for small-scale freshwater prawn larviculture were described. The system comprised a 140 L larval culture tank in line with a 43 L biofilter filled with 24 L of calcareous substrate. Both the tank and biofilter were made of black colored fiberglass in a conical-cylindrical shape. The turnover rate of the water through the system was 24 times a day; water was pumped by airlift. Results of ten larvicultures showed that the system maintained temperature, dissolved oxygen, pH, salinity, ammonium and nitrite stable and suitable to Macrobrachium rosenbergii larvae. Survival and productivity varied from 60.5 to 72.4% and 37 to 72 post-larvae/L, respectively; both were compatible with results of commercial hatcheries. Therefore, this system may be very useful for research purposes or adapted for small-scale post-larvae production.

Crescimento relativo do camarão canela Macrobrachium amazonicum (Heller) (Crustacea, Decapoda, Palaemonidae) em viveiros

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphotypes in male Amazon River Prawns, Macrobrachium amazonicum

The occurrence of morphotypes in Macrobrachium amazonicum males was investigated. Prawns aged 4 to 24 months were taken from 10 aquaculture earthen ponds. Color and spination of right second cheliped were analyzed under a stereomicroscope. Post-orbital and carapace length were measured as well as the length of the cheliped and all limb joints on the right second pereiopods. Four distinct morphotypes were identified: Translucent Claw (TC), Cinnamon Claw (CC), Green Claw 1 (GC1) and Green Claw 2 (GC2). They differed in cheliped morphology and some morphometric relationships. Chelipeds were translucent in TC prawns while in CC they were generally cinnamon-color. Both showed a few spines and some low prominences similar to very small tubercles. GC1 and GC2 showed long moss green chelipeds provided with long and robust spines. However, in GC2, cheliped length was always greater than post-orbital length and the angles of spines on the carpus and propodus were more open, ranging from 51°to 92°, while, in GC1 it varies from 34°to 65°. Cheliped length, the cheliped length/post-orbital length ratio and the spine angle were significantly different among the four morphotypes. A description for the identification of each group is provided and the development of M. amazonicum males is discussed. Each morphotype may play a different role in the population and in the environment in which it lives. Therefore, the identification of morphotypes is advisable for future researches on the biology and culture of M. amazonicum. © 2004 Elsevier B.V. All rights reserved.

Reproductive cycle and fecundity of Potimirim glabra (Kingsley, 1954) (Caridea, Atyidae) from a littoral stream

The reproductive cycle of Potimirim glabra, especially the female size at sexual maturity, reproductive period and fecundity, was studied at two sites of one of the northern littoral streams in the state of São Paulo, Brazil. Prawns were collected monthly for one year. The minmum size at sexual maturity was estimated from the smallest ovigerous female (cephalothorax length = CL), and the reproductive period was determined monthly by examining the relative frequency of ovigerous females. Size comparisons between sampling sites was carried out using the Mann-Whitney u test. The relationship between environmental factors and reproductive aspects was verified using the Spearman's rank correlation. At Site 1, the collected ovigerous females had a CL mean size of 4.24±0.36 mm (n=481); at Site 2, ovigerous females (n=391) had a CL mean size of 5.48±0.49 mm. The reproductive pattern in Camburi is seasonal, with the highest frequency of ovigerous females in February. The frequency of ovigerous females was positively correlated to organic matter content in the substratum, rainfall and temperature. Increased percentage organic matter may indicate greater food availability whereas higher rainfall increases the velocity of the current, thereby aiding the larvae, which depend on brackish water to complete their development, to reach the estuarine region. The temperature acts on the speed of larval development. At Site 1, the mean fecundity obtained was 202±72.31 eggs (90 females; CL from 2.7 to 4.7mm PL), whereas at Site 2, it was 433.3±120.7 eggs (46 females; CL from 4.0 to 5.5mm PL). © 2010 Balaban.